Lathe-chuck.



v Patented Oct. 3|, |899. J., C. POTTER & J. JOHNSTON.

LTHE CHUCK.

,l (Application led Nov. 17, 1898.)

2 sheets-sheet |v ,(No Model.)

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No. 635,976. Patented oct. 3|, |399.

'.1. c. PUTTER @L .1. JDHNsToN. LATHE-cHucK.

. (Application fxled Nov. 17, 1898.)

y (No Model.) 2 Shestsw-Sheet 2.

WITNEEEEE.' v .INUENZ'UEEI mWm/ MQQ@ @2% UNITED STATES PATENT EEicE.

JAMES CHARLES POTTER AND JOHN JOHNSTON, OF PAWTUOKET, RHODE ISLAND, ASSIGNORS TO THEk POTTER da JOHNSTON COMPANY,v OF SAME PLACE.

LAT'H E-c'HucK.

SPECIFICATION forming part of Letters PatentjNo. 635,976, dated October 31, 1899.

Application filed November 17, 1898. Serial No. 696,673. (No model.)

To all whom t may concern:

Be it known that we, J AMES CHARLES POT- TER and JOHN JOHNSTON, of Pawtucket, in the county of Providence and State of Rhode Island, have invented a new and useful Improvement in Lathe-Chucks; and we hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

The invention has reference to an improve*- ment in a chuck adapted to be secured'to the mandrel of a lathe and used to secure the work.

The invention consists in the peculiar and novel construction of the chuck and the mechanism for operating and adjusting the dogs whereby the same may be adjusted independentlof each other, as will be more fully set forth hereinafter.

One object ofthe invention is to facilitate the operation of the dogs by which the work may be secured or released without stopping the lathe. Y

Another object of the invention is to facilitate the adjustment of the dogs and the uncoupling of the dog-operating mechanism.

Figure l is a side view of our improvedy chuck. Fig. 2 is an end view of the same. Fig. 3 is a sectional view of part of the chuck on the line A A of Fig. l. Fig. 4 is a sectional view of part Vof thel chuck on the line B B of Fig. 3, showing the sliding rack-bar engaging with and operating the pinion. Fig. 5 is a sectional-view of part of the chuck on the line O C of Fig. 4.. Fig. 6 is a sectional view of part of thechuck, showing the manner of securing the outer ring to the main portion'of the chuck. Figs. 3, 4, 5, and 6 are shown enlarged.

Similar marks of reference indicate corre# sponding parts in all the figures.

In the drawings, ct indicates the main body of the chuck, consisting of a circular disk,"

from the rear of which extends the hub a', provided with the internal screw-thread c2, by which the chuck is secured to the man.- drel of the lathe. Into the disk a three radially-disposed ductsor ways a3 are bored or otherwise formed, which extend from the periphery of the disk o; to the central Aopening inthe same. Through theface of the disk a the slot c4 is cut or formed, in which the dogs b b b slide. The dogs consist of the bed bf and the rearwardly-projecting brackets h2 and b3. The bed b is provided with rectangular grooves, which bear on the ways b4 b4. The brackets b2 and t? conform to the sectional shape of the duct a3 and fit the same with a sliding iit. The dogs are provided With tapped holes b5 h5, adapted to secure the required jaws to the dogs. Each dog is provided with the screw spindle c, having a threaded screw c of large diameter engaging with the screw-threaded nut formed in the bracket b2. A screw-thread c2 of smaller diameter, formed near the Opposite end, engageswith the 'screw-threaded nut formed in the bracket b3, and the pinion c3 is secured by a spline to the screw-spindle c between the two screw-threaded portions. The pitch of thetwo screw-threaded portions of the screw-spindle, although differing in diameter, is the same. The holes d d extend on each side of the dogs b l) from the front to the rearof .the chuck parallel with the axis of rotation of the chuck. The rack-bard,hav ing at one end the rackdz, is placed in one of the holes d to engage with the pinion c3 on one side or the other of the dog as the chuck may be used to hold the work VJoy expanding or by contracting the same. The position of the parts indicated in the drawings is when the chuck is used as a contracting chuck.

In Fig. 2 the studs cl3 are indicated in broken lines connected with the rack-bars. The stud d3, secured to the rack-bar d', extends through the slot d4 and connects the rack-bar with the sliding sleeve c, on which the shipper-groove c is formed and with which a shipper of the usual form engages to slide the sleeve e on the hub a', and with the sleeve the three rackbars d d to simultaneously operate the three radially-sliding dogs Z) b.

The ring f is secured to the periphery of the disk a, which it fits closely, by the screw f', as is shown in Fig. 6, three such screws f being preferably used to secure the ring f, as

with the ring f.

is indicated in Fig. 2. The ring f is provided with three screw-plugs f 2, forming the j ournal-bearin gs of the screw-spindles c, and each plug is provided with a steel washer f3, forming the thrust-bearing for the screw c'. The plugs f2 are secured by the screws f4, en gaging partly with the screw-plugs and partly The ring g is forced into the central opening in the disk d andis provided at three points with the steel disks g', which form the end thrust-bearings for the screwspindle C.

In assembling the parts the pinion c3 is held between the brackets b2 and b3 and the end of the screw-spindle c, provided with the screw of the smaller diameter c2, is passed through the hole in the bracket h2, and then through the hole in the pinion c3. Then the screws c c2 take into the respective screwthreads formed in the brackets h2 and b3 until the screw-spindle has passed sufticiently through the brackets to allow of the adjustment of the pinion c3 in position to be held by the spline. The screw-spindle is then revolved until the pinion is brought in contact with the bracket b2. The three dogs having been thus assembled are slipped into the ducts (t3, formed in the main body ct of the chuck, from the periphery until they meet in the center. The iinishing-ringf, having been provided with the three screw-plugs f2 and the steel washers f3, is then passed over the main body aand held in position by the screws f. The dogs b b b,carrying the screw-spindle c, are then moved outward from the center to the periphery until the screw c abuts against the steel washers f3 and the ends of the screwspindles c project through the holes in the respective screw-plugs f2. The ring g, provided with the steel disks g', is then forced into place, so that the ends of the screws c2 abut against the disks g. The dogs are now adjusted by turning the screw-spindle c, and to secure perfect adjustment we provide the index h (shown in Fig. l) with a series of equidistant radial lines, there being the same number of lines as there are teeth on the pinion, and the end of the screw-spindle c with an index-mark, so that the exact position of the pinion relative to the brackets Z22 and b3 is clearly indicated. The sleeve c is now placed on the hub a', the rack-bars d are placed in their respective holes d, and the studs d3 are passed through the holes in the sleeve c, through the slots di, and screwed into the respective rack-bars d.

Should it be desirable to adjust the chuck to larger or smaller work or for other reasons, the sleeve c is moved back from the face of the chuck as far as the studs di* can be moved in the slots d, when it will be found that the racks cl2 are out of mesh with their respective pinions c3, when by turning the screw-spindle c any one or all of the dogs may be adjusted as desired, and by reason of the index and mark the teeth of the pinions will be in proper position, so that upon moving the sleeve e forward or toward the face of the chuck, and with it the rack-bars d', the racks d2 will take in to their respective pinions c3 to properly move the dogsb, as desired.

By the use of the peculiar adjusting screwspindle, the pinion secured to the screw-spindle, and the rack-bar the dogs are rigidly held in any position. They may be moved by the sliding sleeve operated by the shipper, and the clamping of the work and the release of v the same are quickly effected by sliding the sleeve c in one or the opposite direction.

I-Iaving thus described our invention, we claim as new and desire to secure by vLetters Patent- 1. In a chuck, the combination with radial ducts and ways for the dogs and the dogs, of screw-spindles each having a pinion secured to the spindle, said screw-spindles being in screw-thread engagement with the dogs, of rack-bars-each engaging with the pinion on one of the screw-spindles, means, substantially as described, for operating the rackbars, and graduated indexes surrounding the end of the screw-spindle; whereby the several screw-spindles may be turned through a predetermined part of a revolution, or revolutions, and the dogs accurately adjusted, as described.

2. In a lathe-chuck, the combination with the disk a, provided with the ducts da and the slots a4 extending tangentially through the disk, and the hub-a', of the dogs b, the brackets b2 and h3 on the dogs fitting the ducts ai with a sliding fit, the screw-spindles c, the screw-threads c' and c2 of different diameter and the same pitch, the pinionc3 connected with the screw-spindle, lthe rack-bars d, the stud d3, and the sleeve @having the groove e adapted to be operated bya shipper; whereby the dogs may be operated to hold and release the work, as described. Y

3. In a lathe-chuck, the combination with the disk Ct, provided with the slots a, the hub a provided with the holes d formed in the ducts d3 extending tangentially through the disk (t, of the dogs b, the brackets b2 and b3 on the dogs fitting the ducts a3 witha sliding Iit, the screw-spindle c provided with the screws Iitting the screws formed in the brackets b2 and b3, the pinion c3 connected with the screwspindle c, the rings f and g, the rack-bars d', the stud d3, and the sleeve e having the groove e adapted to be operated bya shipper; whereby the dogs may be operated to hold and release the work, as described.

4. In a lathe-chuck, the combination with the disk ct, provided with the ducts a3 and the slots a4, the hub a provided with the holes (l formed in the hub, the rings j and g, the washer f3 and the disk g', and the screw-plugs f2, of the dogs b, the brackets b2 and b3 on the dogs fitting the ducts d3 with a sliding fit, the

screw-spindle c provided with screw-threads In Witness whereof We have hereunto set our fol-medito mesh into the screw-threads formed hands.

in the brackets b2 and b3, the pinion c3 secured to the screw-spindle, the rack-bars d', the POTTER studs d3, and the sleeve e having the groove e adapted to be operated by a shipper; whereby Witnesses:

the dogs maybe operated to hold and release B. M. SIMMs,

the Work, as described. 1 J. A. MILLER, Jr. 

